What is, how to build, necessary materials –

If you want a house with high thermal comfort and minimum costs, consider the passive house. The basic aspects for such a building are thermal insulation, estate and ventilation. Find out what the passive house is, how much it costs, what are the right materials and how it is built.

What does the passive house mean?

The passive house has a high energy efficiency, has a high degree of sound insulation and guarantees a constant and pleasant ambient temperature in both summer and winter. The concept was created by the Passivhaus Institute in Darmstadt, Germany.

The buildings can obtain the PH (Passivehaus) certification if it respects some principles and falls within certain rules. The price of the passive house is 10-20% higher than a conventional construction, but the initial investment is amortized much faster.

Unlike a conventional house, passive houses can be more efficient from an energy point of view and 90%. The costs for heating or cooling the building decrease considerably. The aspects that count more in the execution of the project are the positioning of the house, shading, ventilation and isolation.

5 principles of the passive house

In order to obtain international certification (PH Standard – Passive House Institute), the building is subjected to specific tests, including the creation of the necessary primary energy and the degree of thermal insulation and estate. Therefore, the design and construction of a passive house must respect five basic principles.

• Positioning of the building for greater thermal efficiency

Carefully choose the land on which the passive house will be built and place the house as advantageous of the cardinal points. In particular, it is necessary to maximize the energy offered by the sun in winter and limit the heating of the house in the summer months.

Avoid orienting the house to the west, to stay fresh at home in the afternoon with a strong sun. At the same time, the building must benefit from the air currents that cool it in summer and be protected from cold winds in winter. This aspect can be controlled both by the positioning and by the strategic plantation of some trees or shrubs. In addition, keep in mind that the design of the passive house should be made by accredited people.

• Efficient thermal insulation

An important step in the construction of a passive house is thermal insulation. In order to limit heat losses in winter and maintain a low summer temperature, the thermal insulation layer must be continuous and adapted to the climatic area.

The thermal insulation layer for the passive house in Romania should have a thickness of at least 20-30 centimeters, depending on the area and the characteristics of the materials used. For better efficiency, thermally isolate the foundation, the floor, the walls and the roof.

• Elimination of thermal bridges

Thermal bridges are places that favor heat loss: windows and other carpentry elements, support beams, improper isolated roofs (for example in the Sageac area), the balcony structure, the base of the house or the intersection between the foundation and the plate, etc. Read more about the isolation of the base here.

• Seal air circulation

The purpose of the passive house is to prevent heat loss. For the hermetic closure of the space, the windows play an important role. These should have three glass files and a thermal transfer coefficient (U) of the smallest glass. Profiles must also guarantee the estate. The spaces between windows and walls is carefully isolated.

• The air ventilation system with heat recovery

Once isolated and seal the house very well, it is necessary to maintain the air quality inside with a ventilation system with heat recovery (HRV – heat recovery fan). Basically, air circulation is guaranteed without generating heat loss.

In particular, the HRV system filters and warms the air outside, using the hot air removed from the inside. Therefore, the passive house benefits from fresh air and a constant ambient temperature. In addition, such a system can cool the hot air from the outside, even with the help of cold air from the inside.

Houses with energy consumption almost 0

The NZEB standard (almost zero energy building: the house with an almost zero energy consumption) refers to the high energy efficiency of the house. These buildings need energy (heating, cooling, ventilation, lighting and hot water) almost equal to zero.

At the same time, energy comes mainly from renewable sources, such as solar panels for hot water and photovoltaic panels. Another feature of Nzeb houses is the use of intelligent technologies: maintaining air quality, limiting heat losses, lower consumption of electricity SA

The new houses must respect the NZEB standard, according to law no. 372/2005 as regards the energy performance of the buildings. At least 10% of the energy requirement of the NZEB houses are covered with renewable sources.

Different passive house intersects, nzeb if a green house

While a passive house has high energy efficiency due to thermal insulation and sealing, an NZEB construction is based above all on renewable energy. Passive or standard nzeb houses can be considered ecological if they are made with ecological materials.

The green or ecological house has a minimum impact on the environment. It is built with materials that are in abundance of nature and do not affect the environment. In addition, the products necessary for the construction are purchased by local companies to reduce the negative effects of transport.

The construction of a passive house: required materials

For both ordinary and passive houses, it is possible to use the same types of materials. The walls can be made of bricks, BCA or on wooden structure and thermosystem. Conventional materials are used for the roof or other elements of the building. The difference consists in the thermal insulation layer adapted to climatic conditions and efficient sealing.

insulation

Quality thermal insulation is obtained only with some types of materials. For the thermal insulation of the walls we recommend the basalt wool, thanks to its properties higher than the polystyrene or glass vate. See more details in the article «The best basalt wool: how do you choose it?».

To eliminate thermal bridges, thermal base of the house with extruded polystyrene. Depending on the thermosystem, choose the special sticker to glue the vate or polystyrene plates. Other aspects you need to consider are:

• The thermal transfer coefficient λ – smaller, less is the material loses heat. Passive houses should have a value λ lower than or equal to 0.15 w/m²k;
• The thermal resistance R – The greater the value, the greater the loss of heat and the energy efficiency of the passive house. Furthermore, the greater the thickness of a material, the greater the degree of thermal insulation.

For more information on the thermal insulation of the walls, read the article «Thermal insulation of the external walls: complete guide».

Hugeness

One of the basic principles of the passive house is the estate. Both the surfaces and the doors or windows must be tight. Therefore, it is possible to use special products to glue and seal: sealing bands for doors and windows, sealing the silicone for joints, guarantees air circulation with a heat recovery ventilation system.

How to build a passive house: phases to follow

The construction of a passive house follows almost 100% of the stages of the construction of a conventional building. The differences are in design, thermal insulation and seal. Here are the elements you should consider.

Preparation of the project

The project of a passive house must be carried out by a specialized company that satisfies all the criteria imposed by the Passivhaus standard. This phase can take more time than normal, due to every detail to be analyzed, such as:

• positioning the house with respect to the cardinal points;
• the degree of shading of the building;
• Thermal insulation and thermal bridges;
• Sealing and ventilation system;
• the types of materials used and their optimal thickness.

In addition, the energy efficiency of the passive house is calculated with the help of special software: the Phpp (the passive home planning package), which combines numerous tests and calculations. The total energy required for heating, cooling, hot water and electricity must not exceed 60 kWh/m² per year.

Efficient thermal insulation

The largest amount of heat is lost through the walls of a building (about 35%). In general, the walls of the passive house have a greater thickness, determined by the sufficiently voluminous layer of the thermal isolation. Discover from this article what are the advantages of the thermal insulation of the internal walls, which materials are recommended and how to do.

In addition, the roof is thermally isolated with a layer of 30-40 centimeters of mineral wool. The isolation of the Foundation or the floor is not neglected. An important amount of heat can be scattered through these areas (about 10-15%). At the same time, surfaces with high quality products is guaranteed.

seal

Compared to a conventional house, the passive house has a high seal. Thermal bridges are eliminated by the correct isolation of some areas: base, basement, plate, balcony, pipes, etc. Windows are used with very high thermal efficiency. An important step in the construction of a passive house is the installation of the heat recovery ventilation system.

Due to the basic principles of the passive house and respect for some international standards, you can benefit from greater thermal comfort throughout the year and high energy efficiency.